Article
Nanoscience & Nanotechnology
Yanlin Mi, Yinzhou Yan, Mengyuan Wang, Lixue Yang, Jing He, Yijian Jiang
Summary: Researchers have reported a novel hybrid SERS substrate composed of a large microsphere and a small microsphere array with Ag nanoparticles. The cascaded structure allows for increased molecular concentration, enhanced intensity of excitation light, and giant Raman enhancement.
Article
Chemistry, Multidisciplinary
Jeanne Heintz, Nemanja Markesevic, Elise Y. Gayet, Nicolas Bonod, Sebastien Bidault
Summary: This study demonstrates that the strong-coupling regime between quantum emitters and plasmonic resonators can only be achieved under stringent experimental conditions, specifically when the interparticle spacing is less than 2 nm. By actively decreasing the gap between gold nanoparticles to sub-2 nm values through screening electrostatic repulsion at high ionic strengths, the observation of a strong-coupling regime is confirmed through single-nanostructure scattering spectroscopy. Planar facets of polycrystalline gold nanoparticles also play a role in influencing the probability of observing strongly coupled hybrid nanostructures.
Article
Optics
Tulika Agrawal, Soumyodeep Dey, Shubhayan Bhattacharya, Gurvinder Singh, Prem B. Bisht
Summary: This study conducted a numerical investigation on the microcavity-NP system and found that the shape of metal nanoparticles has a significant impact on the output field strength. The splitting of the dipole mode of the nanoparticles was also observed, and the surface enhanced Raman spectroscopy factor was estimated for the nano-cube dimer NP-microcavity hybrid system.
Review
Chemistry, Multidisciplinary
Kenji Hirai, James A. Hutchison, Hiroshi Uji-i
Summary: The exchange of energy between materials and optical fields results in strong light-matter interactions and the formation of polaritonic states with unique properties. Initially studied mostly by physicists using inorganic materials and cryogenic temperatures, recent research has shown that polaritonic states can be achieved at room temperature even in rapidly fabricated metallic optical cavities, making them accessible to chemists, materials scientists, and biochemists. The emergence of exciting phenomena suggests that polaritonic states have genuine relevance in molecular and material energy landscapes.
Article
Physics, Applied
Haneen Akram, M. Abdullah, Amin H. Al-Khursan
Summary: This work utilizes the Green function to investigate the emission spectra of a hybrid metal nanoparticle (MNP) coupled with a double quantum dot (DQD), taking into account the contribution from higher-order plasmonic modes. The results show that the distance between MNP and DQD, as well as the radius of MNP, play an important role in controlling the peak height and position in the spectrum. The significance of the probe field in regulating the peak frequency and height is demonstrated.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Optics
Li Li, Yu-Hao Pan, Yi-Jia Liu, Xiao-Long Zhou, Dong-Yu Huang, Ze-Min Shen, Jian Wang, Chuan-Feng Li, Guang-Can Guo
Summary: This experimental study achieved a strong coupling between a cold atomic ensemble and an optical cavity by using a programmable movable optical dipole trap to load the atomic ensemble into an optical fiber microcavity. By measurement of the vacuum Rabi splitting, a high coupling strength and effective atom number were obtained. This experimental system has important implications for research on cold atomic ensemble and cold molecule based cavity QED.
CHINESE OPTICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Hitoshi Mizuno, Tomomi Jinjyo, Kazuki Bando, Fumio Sasaki, Kenichi Yamashita, Hisao Yanagi
Summary: Microcrystals with different orientations of thiophene/phenylene co-oligomers (TPCOs) were prepared as Fabry-Perot microresonators using a miniemulsion technique. Strong exciton-photon coupling was demonstrated for BP2T and BP2T-CN microcrystals owing to their active microresonators providing effective photonic mode confinement. The strength of the coupling between excitons and photons is correlated with the refractive index and absorption coefficient originating from the transition dipole moment and oscillator strength, with BP2T-CN achieving a larger value of omega due to its higher absorption coefficient, larger refractive index, and smaller mode volume.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Physics, Multidisciplinary
Junhui Cao, Simone De Liberato, Alexey Kavokin
Summary: The vacuum Rabi splitting in semiconductor microcavities scales with the square root of oscillator strength, but a new polaritonic resonance is formed when the Rabi splitting exceeds the stop-band width of the Bragg mirrors. This phenomenon occurs when the material hosting excitons hybridises with the microcavity modes outside the stop-band, resulting in unique polaritonic features.
NEW JOURNAL OF PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Kenji Hirai, Hiroto Ishikawa, Yasufumi Takahashi, James A. Hutchison, Hiroshi Uji-i
Summary: Site-selective chemistry provides new approaches for synthesizing important molecules, and vibrational strong coupling (VSC) can modify the chemical reactivity at specific sites. In this study, actuatable FP cavities were developed to automatically adjust cavity mode energy and maintain maximized VSC during a reaction, resulting in improved site-selective reactivity.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Derek S. S. Wang, Johannes Flick, Susanne F. F. Yelin
Summary: Recent experiments have shown the potential to alter and steer chemical reactions in optical cavities, but the theoretical understanding remains limited. This paper focuses on the unimolecular dissociation reactions of multiple molecules interacting with an infrared cavity mode. The study reveals that increasing the number of aligned molecules can slow down the reaction rate if the cavity mode is resonant with a vibrational mode of the molecules. A scaling relation is also discovered to estimate the onset of reaction rate modification by collective vibrational strong coupling.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Asia Sarycheva, Maruda Shanmugasundaram, Andrey Krayev, Yury Gogotsi
Summary: MXenes are extensively researched materials due to their unique combination of high electronic conductivity and hydrophilic surface. In this study, nanoscale Raman imaging of single-layer and few-layer Hakes of Ti3C2Tx MXene is reported using tip-enhanced Raman scattering (TERS). The absolute intensities of MXene peaks decrease with increasing number of layers, while the relative intensity of certain bands increases. The peak positions of the main MXene bands do not significantly change with different layers, suggesting weak coupling between the MXene layers. The study also reveals the stiffening of vibrations over the wrinkles in MXene Hakes.
Article
Chemistry, Multidisciplinary
Robin R. Jones, Cornelia Miksch, Hyunah Kwon, Coosje Pothoven, Kristina R. Rusimova, Maarten Kamp, Kedong Gong, Liwu Zhang, Tim Batten, Brian Smith, Alejandro V. Silhanek, Peer Fischer, Daniel Wolverson, Ventsislav K. Valev
Summary: Against the backdrop of current healthcare and climate emergencies, surface enhanced Raman scattering (SERS) is gaining popularity as a technique for identifying and fingerprinting molecules in various substances. Researchers have investigated plasmonic nanohelices and found that they possess excellent SERS properties. These nanohelices can be produced at a low cost, exhibit strong and uniform Raman enhancement effects, and are anticipated to have broad applications in surface enhanced Raman spectroscopies and material science.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Adam Weissman, Maxim Sukharev, Adi Salomon
Summary: We demonstrate strong coupling between a single or few J-aggregates and an inverse bowtie plasmonic structure, resulting in the formation of three hybrid modes. The magnitude of the Rabi splitting, up to 290 meV, depends on the orientation of the J-aggregate with respect to the symmetry axis of the plasmonic structure.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Eitan Oksenberg, Ilan Shlesinger, Gokcen Tek, A. Femius Koenderink, Erik C. C. Garnett
Summary: The surface-enhanced counterparts of Raman scattering (SERS) and infrared (IR) absorption (SEIRAS) are commonly used to probe and identify nanoscale matter and small populations of molecules. In this study, a complementary surface-enhanced vibrational spectroscopy approach is presented to probe the vibrational signature of metal-bound molecular monolayers. Nanocavities are designed and produced with sharp and tunable visible (VIS) and mid-IR gap resonances by placing nanorods on a mirror that is coated with a thin dielectric spacer.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Wenbo Zhang, Jia-Bin You, Jingfeng Liu, Xiao Xiong, Zixian Li, Ching Eng Png, Lin Wu, Cheng-Wei Qiu, Zhang-Kai Zhou
Summary: This study reports a room-temperature diexcitonic strong coupling (DiSC) nanosystem in which the excitons of a transition metal dichalcogenide monolayer and dye molecules are both strongly coupled to a single Au nanocube. The results show that coherent information exchange can be observed even when the exciton energy detuning is about five times larger than the respective line widths. The strong coupling behaviors in such a DiSC nanosystem can be manipulated by tuning the plasmon resonant energies and the coupling strengths, opening up a paradigm of controlling plasmon-assisted coherent energy transfer.
Article
Multidisciplinary Sciences
Philip A. Thomas, Kishan S. Menghrajani, William L. Barnes
Summary: The authors demonstrate that phase singularities can be created and controlled, all optically, in a simple thin film of organic molecules using cavity-free strong light-matter coupling. This finding not only opens up new possibilities for the application of strong light-matter coupling, but also provides a new, simplified, and more versatile means of manipulating phase singularities.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Adarsh B. Vasista, Eduardo J. C. Dias, F. Javier Garcia de Abajo, William L. Barnes
Summary: The emergence of dielectric open optical cavities has provided a new research direction in nanophotonics. Dielectric microspheres can support a variety of cavity modes and are ideal for studying molecule-cavity interactions. Understanding molecule-cavity coupling and the role of spatial mode profiles is essential for optimizing the coupling strength.
Article
Materials Science, Multidisciplinary
Irati Alonso Calafell, Lee A. Rozema, Alessandro Trenti, Justus Bohn, Eduardo J. C. Dias, Philipp K. Jenke, Kishan S. Menghrajani, David Alcaraz Iranzo, F. Javier Garcia de Abajo, Frank H. L. Koppens, Euan Hendry, Philip Walther
Summary: This study investigates high-harmonic generation in graphene heterostructures and discovers that metallic nanoribbons can amplify near-field effects in the graphene layer, allowing the observation of third- and fifth-harmonic generation in the mid-infrared pump power. The study also finds that ribbon width, spacer thickness, pump power, and polarization have an impact on the nonlinear signals, and demonstrates enhancement factors for third- and fifth-harmonic generation relative to bare graphene.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Chemistry, Physical
Wai Jue Tan, Philip A. Thomas, William L. Barnes
Summary: In the absence of strong coupling, an anticrossing phenomenon is observed in planar silver/dielectric structures near the epsilon-near-zero point due to impedance matching between the silver and dielectric layers.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Optics
Hyeonwoo Lee, Mingyu Lee, Hyeung Joo Lee, Juwon Yoon, Kishan Dholakia, Kyunghwan Oh
Summary: In this study, a novel all-fiber Bessel-like beam generator (BBG) was proposed and experimentally demonstrated to transport a dielectric particle over a distance exceeding 2mm. This was achieved by optimizing the multimode interference (MMI) in the BBG structure to create a Bessel-like beam with a propagation invariant length (PIL) and selecting an appropriate laser wavelength to suppress thermal effects. The impact of varying the diameter of the MMI region on the PIL and the transverse intensity profile of the Bessel-like beam was analyzed. This research paves the way for fiber optic applications such as novel beam shaping, optical transport, and optical imaging.
OPTICS AND LASERS IN ENGINEERING
(2023)
Article
Physics, Multidisciplinary
A. M. Paniagua-Diaz, W. L. Barnes, J. Bertolotti
Summary: This work investigates how much energy from a fully developed speckle pattern can be converted into a high quality (low M (2)) beam using wavefront shaping. The study provides a theoretical framework and discusses the advantages and limitations of this approach.
Article
Biochemical Research Methods
George O. Dwapanyin, Darren J. X. Chow, Tiffany C. Y. Tan, Nicolas S. Dubost, Josephine M. Morizet, Kylie R. Dunning, Kishan Dholakia
Summary: Embryo quality is a crucial factor for live birth outcomes, but a reliable diagnostic method for embryo quality is still lacking in the IVF clinic. In this study, we demonstrate that digital holographic microscopy (DHM) can rapidly and non-invasively assess the refractive index of mouse embryos, providing valuable information about their lipid content. DHM detected spatio-temporal changes in refractive index during embryo development, reflecting the accumulation of intracellular lipid, which is known to compromise embryo health. DHM may offer a promising non-invasive diagnostic method for accurately assessing embryo quality.
BIOMEDICAL OPTICS EXPRESS
(2023)
Article
Multidisciplinary Sciences
Gavrielle R. Untracht, Mingzhou Chen, Philip Wijesinghe, Josep Mas, Harold T. Yura, Dominik Marti, Peter E. Andersen, Kishan Dholakia
Summary: The penetration depth of optical coherence tomography (OCT) is greater than conventional microscopy, but signal reduction with depth is a challenge. This study explores the role of multiple scattering in OCT image contrast and introduces a geometry that separates the incident and collection fields, enhancing contrast at depth. Theoretical and experimental results demonstrate a significant improvement in contrast, with a ninefold enhancement observed in biological samples.
Article
Physics, Multidisciplinary
Yoshihiko Arita, Stephen H. Simpson, Graham D. Bruce, Ewan M. Wright, Pavel Zemanek, Kishan Dholakia
Summary: By studying the rotation of birefringent microspheres trapped in vacuum and set into rotation by circularly polarised light, the authors explain the stable translational motion exhibited by these spheres. They demonstrate that fast rotation reduces the effect of azimuthal spin forces, resulting in nano-scale limit cycles at reduced pressures. This research has implications for designing high-stability rotors with enhanced centripetal loads and improving cooling methods for autonomous limit cycle oscillations, potentially leading to the study of non-equilibrium quantum effects.
COMMUNICATIONS PHYSICS
(2023)
Article
Optics
Jerin Geogy George, Kishan Dholakia, Shanti Bhattacharya
Summary: In this paper, a design and generation method for sidelobe-suppressed Bessel-like beams (SSBB) is described, which enhances the contrast for light-sheet imaging by suppressing the sidelobes. The interference of two Bessel beams with slightly different wavevectors is used to achieve this sidelobe suppression. The designed phase function can be realized using a spatial light modulator to generate the SSBB.
Article
Optics
Roopam K. Gupta, Nils Hempler, Graeme P. A. Malcolm, Kishan Dholakia, Simon J. Powis
Summary: T cells of the adaptive immune system are effectively protected against pathogenic challenges. Traditional labelling methods are time-consuming and expensive, but digital holographic microscopy with deep learning proves to be a faster and more cost-effective alternative. The combination of DHM and deep learning achieves high throughput and accuracy in classifying CD4+ and CD8+ T cell subsets.
Article
Chemistry, Multidisciplinary
Philip A. Thomas, Wai Jue Tan, Vasyl G. Kravets, Alexander N. Grigorenko, William L. Barnes
Summary: This study re-examines the impact of infrared strong coupling on photoisomerization rates and finds that the variations observed can be attributed to the absorption of ultraviolet radiation in the cavity, rather than strong coupling. The results highlight the importance of ruling out non-polaritonic effects in cavity-based experiments.
ADVANCED MATERIALS
(2023)
Article
Optics
Xiao-Yong Duan, Graham D. Bruce, Feng Li, Kishan Dholakia
Summary: We analytically demonstrate the existence of an asymmetric optical binding force between two identical particles. This force arises from the asymmetric forward and backward scattering due to the coupling interactions between electric and magnetic dipoles. We show the rich dynamics of this phenomenon and discuss the conditions for the emergence of the asymmetric binding force.